Cranes having boom systems are known in the prior art. On the assembly of corresponding cranes, the boom elements of the boom system are moved or telescoped from an assembly state to a fully assembled state. The assembly state can in this respect, for example, be a state in which the boom system is substantially placed on a storage area or a ground area. The crane is not able to carry out crane work in this respect. The fully assembled state is achieved after a corresponding moving of the boom elements. The boom system can in this respect substantially be removed from the storage area or ground area and can be arranged at least partly angled from the storage area or ground area. Parts of the boom system such as a main boom can in this respect be arranged substantially vertically.
One potential issue with the moving of the boom system is that the moving of a boom system is a complex sequence of movements which has to be carried out reliably so that no toppling over of, or damage to the crane occurs. This requires experienced operating staff and a high time effort in the carrying out of the moving. It is therefore the object of the present disclosure to simplify the moving of a crane of the category or to simplify its boom system and to improve the movement procedure.
This object is achieved in accordance with the present disclosure by a method for the automatic telescoping of the boom system of a crane, in particular of a mobile crane, having at least one telescopic boom, and having a rope and winch for pivoting the boom, the method comprising the steps of measuring with a first sensor an actual value of the boom angle of the boom forming an acute angle relative to a horizontal plane; and actuating, in particular automatically, the winch in dependence on the measured boom angle.
It is hereby advantageously made possible to monitor and/or to regulate/control the telescoping of the boom system in a simplified manner such that a tilting of or damage to the crane is prevented.
It is conceivable in this respect in an example embodiment that at least one desired value of the boom angle is predefined and that the winch unwinds in an accelerated manner on the telescoping out of the boom if the actual value exceeds the desired value and the winch may unwind in a delayed manner on the telescoping out of the boom if the actual value falls below the desired value. Alternately, the winch may wind up in a delayed manner on the telescoping in of the boom if the actual value exceeds the desired value and the winch may wind up in an accelerated manner on the telescoping in of the boom if the actual value falls below the desired value.
The angle between the boom or the main boom of the crane and the horizontal (that is, the ground) can in this respect be represented by the boom angle. Desired values which are different or the same can in this respect be predefined for every equipping state of the crane. Desired values which are different or the same can equally be predefined for the telescoping in and for the telescoping out of the boom.
The detection and measurement of the actual value of the boom angle of the boom in this respect allows a monitoring of the crane kinematics especially adapted to the crane geometry and to the weight distribution. The boom angle can, for example, be determined from measured values from angle transmitters at the boom. The guying which serves the stabilization of the boom system can in this respect be tensioned so that the forces transmitted by the guying can likewise be used for monitoring the crane kinematics.
In another example embodiment, the method further comprises the steps of measuring with a second sensor an actual value of the guying frame angle of a guying frame forming an acute angle relative to the horizontal plane by determining, based on the measurements of the boom angle and the guying frame angle, the intermediate angle of the guying frame and of the boom; and actuating, in particular automatically, the winch in dependence on the intermediate angle of the guying frame and the boom.
In accordance with this example embodiment, a crane can also be telescoped in accordance with the method, in which crane and the winch is arranged, for example, at a revolving deck of the crane and not at a co-moved boom element such as the telescopic boom itself. In this respect, the intermediate angle is now determined as the control parameter and the winch is actuated so that limit values are not exceeded. In this respect, that angle is represented by the intermediate angle which is spanned between the guying frame and the boom.
It is conceivable in a further example embodiment that at least one desired value of the intermediate angle is predefined and that the winch winds up on the telescoping if the actual value exceeds the desired value. Additionally or alternatively, the winch may unwind on the telescoping if the actual value falls below the desired value. Additionally, or optionally, the winch may be automatically actuated on a luffing of the boom.
It is advantageously hereby avoided that the intermediate angle of the guying frame and of the boom becomes too small or too large, whereby the stability of the crane could be reduced. Additionally or alternatively, it can be ensured by the actuation of the winch on the luffing of the boom that the rope or the guying follows the luffing movement of the boom and does not counteract it, or that a correct guying can be ensured despite a luffing movement taking place.
It is conceivable in a further example embodiment that the hook height relative to the ground and/or the luffing tip angle relative to the ground or relative to the boom and/or the force carried by a guying and/or support is measured as an additional control parameter. It is conceivable in another example embodiment that the boom system is controlled on moving such that the at least one control parameter and/or the actual value or the actual values is/are within specific intervals or within a specific interval at least at times during the moving.
The crane or individual crane drives can then be controlled, in particular automatically, such that the corresponding control parameters are held within specific intervals. This means that the hook height is automatically held at level on the telescoping and/or that the luffing tip likewise automatically maintains a constant angle relative to the ground or to the horizontal on the telescoping. Analogously, the force carried by the guying and/or support can also be automatically held constant by a corresponding control of crane drives or of a crane drive. The operation of the crane is hereby facilitated for the operating staff on its assembly and the risk of an incorrect assembly at which the crane can topple over or can be otherwise damaged is minimized.
Further advantages and details of the method will be shown with reference to the Figures.